Photo-Biofuel Cell-Based Self-Powered Sensors for Food Safety

Photo-biofuel-cell (PBFC) self-powered sensors are emerging as effective tools for food safety analysis because light-driven charge generation can be directly coupled with redox catalysis to produce bias-free signals with inherent amplification in complex matrices. Unlike photoelectrochemical sensors that commonly depend on external biasing or sacrificial reagents and biofuel cell sensors restricted by limited driving force and catalyst instability, PBFCs function as closed energy signal systems in which photovoltage and interfacial reaction pathways jointly govern signal output. This review consolidates recent progress by relating photocarrier behavior, interfacial field regulation, and cathodic charge utilization to analytical sensitivity, operational stability, and matrix tolerance. Material and interface strategies across photoanodes, photocathodes, and recognition layers are examined, including band structure modulation, heterojunction construction, conductive architectures, and interface gating for controlled charge transfer upon target binding. Representative applications involving antibiotics, pesticides, heavy metals, and toxins are discussed with attention to dual photoelectrode operation, microfluidic regulation, and ratiometric or multiplex readouts. These developments indicate that PBFCs are advancing toward reliable on-site sensing in real food matrices.